Multiple processes in chemistry employ a solid stationary phase for purification, filtering or separation of reagents or reagent mixtures. Conventional implementations may include columns packed with a resin containing beads or porous media of a certain size, with a functionalized surface, and/or specific material properties. Solid stationary phases are often implemented in chromatography. For example, solid stationary phases may be used in partition, normal-phase, displacement, reversed-phase, size-exclusion, ion-exchange and bioaffinity chromatography. Other implementations are solid phase extraction (SPE) and ion exchange columns as they are used e.g. in radiochemistry for purification and concentration of radioactive species.
Microfluidic technology has applications in chemistry, biochemistry, biology, physics and pharmaceutics. Microfluidic techniques typically involve small sample volumes, e.g., in the range of several nanoliters to hundreds of microliters, and offers advantages such as low reagent consumption, efficient thermal control, small system footprint at a high level of functionality integration and versatile, disposable microfluidic core components. Whereas microfluidic systems have developed over several decades, only a few microfluidics based products have succeeded and entered the market. Challenges in microfluidics may relate to system reliability, the micro-to macro interface, system control, readout, overall system complexity, manufacturing complexity and resulting cost of microfluidic consumable products, and the implementation of conventional chemical methods utilized during analysis, synthesis and purification of chemical compounds. With regard to the incorporation of chemical techniques into microfluidic environments, the implementation of stationary phases and beads onto microfluidic chip devices suitable for mass production is particularly challenging.